Stacking and mobility of cationic amphiphiles in the complex with DNA and DNA transfection activity of the complex

摘要: Cationic amphiphiles, which have a quaternary ammonium head, hydrocarbon tails and glutamic acid connector with methylene and/or phenylene spacer, been used to deliver DNA into eukaryotic cells. The relationship between the mobility of various synthetic cationic amphiphiles complexed their transfer activities has been examined. When plasmid was added liposomes formed cationic amphiphiles and treated DNase I, found be completely resistant to digestion suggesting that is enclosed in liposomal vesicle formed by amphiphiles. CD spectra due chiral phenylene chromophore of the amphiphiles showed amphiphile–DNA complexes with higher transfection activity exhibited disordering stacking the amphiphiles by formation complex at culture temperature. Study the NMR signal protons methylene terminal methyl groups the hydrocarbon chain amphiphiles indicates of the chain restricted by binding cationic headgroup DNA at lower than phase transition temperature amphiphiles. Based on these results those on gene the complexes, we discuss relationship amphiphile–DNA interaction in the transfection complex, and conclude that most important requirement for efficient transfection is that amphiphiles are fluid bilayer culture temperature cells.